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The present study reports for the first time the use of biobased chitosan-polybenzoxazine (CTS-PBZ) as a precursor for high CO 2 adsorbing carbon aerogels (CAs). Montmorillonite (MMT) is used to reinforce the CTS-PBZ aerogel. MMT-CTS-PBZ nanocomposite aerogels are synthesized using the freeze-drying technique and then cross-linked via ring-opening polymerization of benzoxazine followed by carbonization at 800 °C. Polybenzoxazine improves the structural stability for removing CO 2 from the environment even at a high pressure. The properties of polymeric and nanocomposite aerogels have been evaluated using X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The microstructure of the CAs is characterized by N 2 adsorption−desorption measurements. The CAs exhibit mesoporous materials with pore sizes in the range of 2−7 nm and high BET surface area. The total pore volume of CAs is as large as 0.296 cm 3 g −1 , and the maximum BET surface area is 710 m 2 g −1 . Breakthrough curves of CO 2 adsorption show high CO 2 adsorption capacity at ambient conditions and excellent CO 2 adsorption−desorption reversible performance with a maximum of 5.72 mmol g −1 . Adsorption isotherms and thermodynamic properties of CO 2 adsorption are described.

A novel class of polymer blends has been prepared from main-chain-type benzoxazine polymer (MCBP) and chitosan (CTS), a modified biomacromolecule. A water-soluble, main-chain-type benzoxazine polymer, MCBP(BA-tepa), was synthesized from the reaction of bisphenol A (BA), tetraethylenepentamine (TEPA) and formalin. The structure of the MCBP(BA-tepa) was confirmed by proton nuclear magnetic resonance spectroscopy ((1)H NMR) and Fourier transform infrared spectroscopy (FT-IR). The polymer blends were prepared by mixing MCBP(BA-tepa) and CTS in aqueous acetic acid solution (1%). The CTS/MCBP(BA-tepa) films are cross-linked by thermal treatment via the ring-opening polymerization of benzoxazine structures in the main chain to produce an AB-cross-linked network. Differential scanning calorimetry (DSC) and FT-IR were used to study the effects of CTS on the polymerization behavior of benzoxazine. Hydrogen bonding between polybenzoxazine and CTS structures was also observed. The mechanical and thermal properties of cross-linked CTS/MCBP(BA-tepa) films were evaluated, and the results showed unusual levels of synergism. In particular, the tensile strength and thermal stability were significantly enhanced in a nonlinear fashion.

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